Sliding-door fastener and buffer.



E. SGHMID.

SLIDING DOOR PASTENER AND BUFFER.

APPLICATION FILED JULY 1,

Patnted Sept. 9, 1913.

Nrrnn sfrarns arfr oren.

EMIL scHivrIn, or Twnyrive egg, nrsrmc'rworfcolall/ Ira SLIDING-DOOR FASTENER AND BUFFER.

To all whom 25 may concern Be it known that I, EMIL SC-HMID, a citizen of the United States, residing at Twining City, in the District of Columbia, have invented certain new and useful Improvements in Sliding-Door Fasteners and Buffers; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to locks and latches and as such is capable of general use, but has reference more particularly to sliding door fasteners for use in connection with elevator service where prompt, reliable dooraction and an absence of jarring noises are of utmost importance.

One obj ect of the present invention, therefore, is the production of a light, durable and efficient elevator door fastener, equipped with a friction brake of novel construction, capable of absorbing the shocks incident to sudden closing of doors, and of noiselessly performing all the desirable Jfunctions of the usual rubber or spring bumpers, without the customary rebound of the door and consequent noises.

As a further object my invention contemplates the production of a door fastening or latch mechanism of simplified construction not likely to become deranged, applicable to right and left hand doors alike, and provided with self-contained braking or buiflng means automatically actuated and graduated as to its resistance according to requirements.

With these and other objects in view the present invention further consists in certain novel features of construction and combinations of parts which will be hereinafter particularly described and pointed out in the claims following.

In the accompanying drawings which form part of this application for Letters- Patent, and whereon like characters indicate corresponding parts in the several views: Figure 1 is a side elevation of my invention with the face plate removed, showing the latch-bolt retracted and other parts in normal position when door is open. Fig. 2 is a view corresponding with Fig. 1, except that here the latch-bolt projected is in engagement with a coperating strike-plate or keeper the latter being shown in section. Fig. 3 is a sectional view of the device taken Specification of Letters Patent.

Application filed July 1, 1913.

Patented Sept. 9,1913.

Serial No. 776,750.

on the line 3 3, Fig. 1, and Fig. 4 is a detailed perspective view showing one brake or friction shoe detached.

Reference being had to the drawings and numerals thereon, 1 indicates a metallic casing preferably of cast iron and of rectangular or other convenient outline, having an opening 2 therein for the lingers of an operator, and bolt or screw holes 3 adjacent to its corners for attachment of a face plate 4 substantially corresponding with the backplate of said casing. Rising from the back of casing 1, and cast integral therewith, are pivotal bosses 5 and 6, a spring seat 7 and oppositely disposed brake-shoe guides S, 8, all for purposes which will later appear, while the front or advance edge of casing 1 is broken at top and bottom by apertures 9 and 10, respectively.

Pivotally mounted upon boss 5 is a rock lever 11 having sockets 12 and 13 at opposite ends thereof, the former receiving in pivotal relation the inner cylindrical end 14 of a buffer 15. The said buffer, preferably of brass, projects outwardly through aperture 9, is provided on its upper surface with a lug 16 to limit its outward movement, and has a downwardly beveled under surface 17, as shown. lVithin socket 13 of rock-lever 11 is similarly mounted the cylindrical inner end 18 of a latch-bolt 19 the opposite or advance end whereof projects through aperture 10, has a pyramidal extremity 20 and a downwardly extending latch member 21.

Between guides 8, 8 is located a frictionblock or brake-shoe 22 preferably of gray iron or steel having a smooth upper friction surface 23, limit lugs 24, 24, at opposite sides of its base, and a spring seat 25 between said limit lugs. Resting at one end in the spring seat 7 of casing 1, and at its opposite end in the spring seat 25 of frictionblock 22, is a relatively stiff spring 26 normally holding block 22 up to the limit of its movement, governed by the side lugs 24, 24 aforesaid, as shown by Fig. 1, while nested within spring 26 is a lighter latch spring 27 curled so as to engage and normally exert itself against both rock-lever 11 and latchbolt 19 to normally retain them in the positions shown by Fig. 1. t

Upon boss 6 within and adjacent to the lower rear corner of casing 1 is pivotally mounted an angular hand lever 28, one arm 29 whereof projecting upward crosses hand opening 2 of said casing within reach of an operator, and the other arm 30 whereof has an upturned extremity 31 resting beneath latch-bolt 19 and adapted to raise or unlatch same when occasion requires.

Adjacent to casing 1 and secured to a door frame (not shown) in the ordinary way, is a strike-plate 32 having upper and lower rectangular openings 33 and 3i respectively in its front edge or face each being undercut as at 35, and the former bridged as at 3G as shown by Fig. 2. Crossing the said bridge 3G and entering at each side thereof the undercut portions 35 of opening 33, is a layer or layers 37 of yielding pliable material such as rubber or canvas and rubber which serves as a preliminary shock absorber, and receives the initial thrust of buffer 15, as will now more fully appear' in a brief description of operation.

My invention in its preferred form of construction being substantially as shown and described, its operation is substantially as follows when applied to an elevator door, for example, with keeper 32 aiiiXed to the elevator door-frame or cage: An operator inserting the fingers of one hand through lock opening 2 engages arm 29 to throw the bell crank operating lever 28 upon its pivotal support 6 thus elevating its angular extremity 31, and lifting latch-bolt 19 against spring 27 a sutiicient distance to clear strikeplate 32 thus permitting the door to be opened by sliding laterally and bodily as usual. Operating lever 29 now being released the latch-bolt 19 returns, under influence of spring 27, to its normal position shown by the drawings. Upon closing, with the lock parts in the position indicated by Fig. 1, buffer 15 first impinges upon pads 37 and is partially depressed to the position shown by Fig. 2 or until its under beveled surface impinges upon the friction surface 23 of brake shoe 22. During this movement lever 11 is rocked against the resistance of spring 27 to the position indicated by Fig. 2, thereby projecting latch-bolt 19 until it engages strike-plate 32 as the door closes and is seated by action of spring 27 in locked position with relation to the keeper 32, as shown.

The foregoing is the operation under ordinary and normal conditions, but when as frequently happens the door is closed with unusual and unnecessary force, brake shoe 22 is then automatically called into service to absorb shocks and prevent noise, as also rebounding of the door in the following manner: After assuming the relative position of parts shown by Fig. 2, any further forcible inward or closing movement of the door is resisted by spring 2G, brake shoe 22, and buffer 15, for, as said butler, in engagement at its outer extremity with pads 37, is forced farther inward, its lower inclined friction surface 17 depresses brakeshoe 22 which in turn is resisted by the relatively stiff spring 26 thereby checking and iinally stopping advance movement of the door. And, moreover, it will be noted that owing to the angle of the friction surface 23 upon block 22, and that of the coacting surface 17 upon buer 15 the desired frictional resistance is steadily and gradually increased exactly in accordance wit-h requirements, while on the other hand this fri ctional resistance is as steadily and gradually decreased when buffer 15 is projected or returned to its normal position either by reopening the door, or by a partial opening as when arebound of the door is checked, so that in either case the movement of the door is gradually and noiselessly first checked and then arrested.

It will thus be seen that the braking action of shoe 22, in connection with spring 26 and correlative parts, ensues when excessive force is applied in the act of closing doors equipped with my invention, and that under all ordinary conditions shocks and sounds are sufciently absorbed by agency of the pads 37, but even under these conditions a slight depression of buffer 15 performs the useful function of automatically advancing latch-bolt 19 to assist it in reaching for and properly engaging the strikeplate 32.

This being a description of my improvements in one form of embodiment it should be further noted that the spirit of my invention would not be departed from if a plurality of brake-shoes or friction-blocks 22 were employed bearing upon opposite sides of a buer 15, or a modified form of such buffer; or, if the latch were secured to the door-frame and the keeper to the door, and in like manner various changes of construction and arrangements of component elements could be made and substituted without materially altering their use and operation.

Having thus set forth my invention, what I now claim and desire to secure by Letters Patent is:

l. In a door lock the combination with a casing, a latch, and a reciprocating buffer;

of means for resisting the reciprocation of said buffer in both directions.

2. In a door lock the combination with a casing, a latch, and a reciprocating buffer; of a friction block for resisting the reciprocation of said buffer in both directions.

3. In a door lock the combination with a. casing, a latch, and a reciprocating buffer; of a spring-pressed friction block for resisting the reciprocation o-f said buffer in both directions.

4. In a door lock the combination with a casing, a reciprocating latch, and a reciprocating buffer; of a friction block for resisting the reciprocation of said buffer, and

lock case and pivota-lly connecting the inner ends of said latch and buffer, and a spring bearing upon said latch and rock lever whereby they are retained in their relative normal positions.

In testimony whereof I affix my signature, in presence of two subscribing witnesses.

EMIL SCHMID.

lVitnesses:

WM. E. DYRE, EDWIN L. BRADFORD.

Copies of this patent may be obtained for ive cents each, by addressing the Commissioner of Patents, Washington, D. C. 

